How to set up a disk in qemu?

Question

ubuntu

I want to put a virtual machine on qemu, previously I worked only with virtualbox.
On the move

fdisk -l 2017-07-05-raspbian-jessie-lite.img

stopped because I don't understand what exactly this command will do. From the description, I know that it distributes the disk. It needs to be done on the host and I have concerns that I might break the main system.
Or am I worrying for nothing and this command will only create a disk like the os.vdi files, like virtualbox creates, without affecting the main disk in any way?

Answer 1

https://linux.die.net/man/8/fdisk

-l
List the partition tables for the specified devices and then exit. If no devices are given, those mentioned in /proc/partitions (if that exists) are used.